# git rev-parse -q --verify d497ebf5fb3a026c0817f8c96cde578787f24093^{commit} d497ebf5fb3a026c0817f8c96cde578787f24093 already have revision, skipping fetch # git checkout -q -f -B kisskb d497ebf5fb3a026c0817f8c96cde578787f24093 # git clean -qxdf # < git log -1 # commit d497ebf5fb3a026c0817f8c96cde578787f24093 # Author: Frederic Barrat # Date: Mon Jun 18 14:14:36 2018 +0200 # # ocxl: Fix page fault handler in case of fault on dying process # # If a process exits without doing proper cleanup, there's a window # where an opencapi device can try to access the memory of the dying # process and may trigger a page fault. That's an expected scenario and # the ocxl driver holds a reference on the mm_struct of the process # until the opencapi device is notified of the process exiting. # However, if mm_users is already at 0, i.e. the address space of the # process has already been destroyed, the driver shouldn't try resolving # the page fault, as it will fail, but it can also try accessing already # freed data. # # It is fixed by only calling the bottom half of the page fault handler # if mm_users is greater than 0 and get a reference on mm_users instead # of mm_count. Otherwise, we can safely return a translation fault to # the device, as its associated memory context is being removed. The # opencapi device will be properly cleaned up shortly after when closing # the file descriptors. # # Fixes: 5ef3166e8a32 ("ocxl: Driver code for 'generic' opencapi devices") # Cc: stable@vger.kernel.org # v4.16+ # Signed-off-by: Frederic Barrat # Reviewed-By: Alastair D'Silva # Acked-by: Andrew Donnellan # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < git log --format=%s --max-count=1 d497ebf5fb3a026c0817f8c96cde578787f24093 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+NO_ALTIVEC_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc64_defconfig # Added to kconfig CONFIG_ALTIVEC=n # Added to kconfig CONFIG_PPC_TRANSACTIONAL_MEM=n # yes \n | make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+NO_ALTIVEC_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe yes: write error # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+NO_ALTIVEC_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1256:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2497:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1819:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/swap_state.c: In function '__add_to_swap_cache': /kisskb/src/mm/swap_state.c:135:5: warning: 'error' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/bridge/br_netlink.c: In function 'br_afspec': /kisskb/src/net/bridge/br_netlink.c:637:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1433:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2046:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:251:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:231:19: note: 'i' was declared here /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1835:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1745:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/powerpc-next_ppc64_defconfig+NO_ALTIVEC_powerpc # Build took: 0:02:46.261345